Thursday, 20 August 2015

Trends in Climate Change

Trends in Climate Change

Yesterday as well as rising sea levels, the pre-amble to the sequence on BBC Radio Jersey described “wildfires” as a consequence of climate change! Really?

There was recently a wild fire at Les Landes. It does not take much for the gorse to get tinder dry, and this happens every year. What does set it on fire – as happened at Les Landes – is man made as a result (for example) of someone carelessly throwing away a cigarette butt, still smouldering. It is not exactly connected with climate change, and it looks as if the merry jingle cataloguing disasters was pinched from elsewhere – maybe places like Spain or California, where they really do have wild fires raging.

Yesterday we had something even odder. We were told that young children were an age group vulnerable to climate change – in particular flooding and heat. Now heat I can understand – like older people, the body’s regulation of heat in the young is not as good as that of most adults, and they are vulnerable to extremes of cold and heat. But – flooding?

I pictured to myself the flood waters rising to the necks of small children and then over the tops of their heads, while to adults standing nearby, it was only reaching waste height! At any rate, no explanation was given as to how young children were vulnerable to flooding, particularly in Jersey, which after all was supposed to be the focus of the story.

At present, there is no measurable increase in sea levels around Jersey, but there is more unsettled weather, and a greater coincidence of high winds, heavy rain, and high tides – the elements for flooding on the lower coastal areas.

Sceptics will point to extreme weather in the past, and it is important not to ignore these facts. Two years before the idyllic long summer heat wave of 1976, Jersey was being battered by severe weather, twice in one year.

This makes it important to look at trends, of looking at clusters of bad weather events and their frequency over a number of years. Two dice, after all, when thrown twice will come up sometimes with two sixes. But if the dice are weighted, as we may well suspect they are because of climate change, one would expect to see a greater occurrence of sixes than was hitherto the case, or could be expected by chance.

A statistical study in 2014 by Dr Erich Markus Fischer showed that extreme heat waves and heavy rain storms are already happening with increasing regularity worldwide. The chart above shows the annual frequency of North Atlantic Tropical storms. The chart goes up and down, but the overall trends is upward, and sharply. We are in a period of very nasty unsettled weather.

Locally, the late Tony Pallot, Principal meteorological officer has said in 2014 that while the recent conditions are not unusual in themselves, bad weather is becoming more common.

And another report shows that so-called “blocking patterns”, where hot or wet weather remains stuck over a region for weeks causing heat waves or floods, have more than doubled in summers over the last decade. That's certainly something effecting us in Jersey.

Even the sceptics must admit that change to more extreme weather is occurring, even if they deny its cause. The fact remains, however, that regardless of the acceptance or not, that sea defences need to be looked at to improve greater resilience against bad weather.

What sceptics do is to point to bad weather events of the past, to show that it happened then. That is why statistical trends are more important than singular occurences.

An example is the severe weather of 1974, demonstrating that extremes of weather have occurred in the past, even if their frequency, taken as a long term trend, is increasing year on year. The Almanac report was as follows:

January 28 1974: The motor yacht Naomi sank in Gorey Harbour last might after she broke loose from her moorings in the gale-force winds. Only the cabin top of the yacht, owned by Major-General J. H.O. Wilsey, of Maufant Manor, was visible early this morning, and Gorey Harbour attendant, Mr. Doug Park, said that the vessel was badly damaged.

January 29-Although the petrol tanker Esso Tynemouth has been sheltering off the Isle of Wight since the weekend and is not expected to reach the Island until tonight, Esso say they have plenty of petrol in store.

The tanker, carrying 520 tons of petrol for the Island, has been unable to complete her journey from Fawley because of gales.-The Defence Committee announced that the Island had almost met the required reduction in the use of all fuels, said that the saving in petrol usage only amounted to 5 ½ per cent last week. A further call to motorists not to use their cars for non-essential journeys was made,

February 9: Rough seas and winds gusting to gale force caused chaos on Jersey’s low-lying south coast this morning when they combined with a 39 ft high tide. For more than an hour, parts of the of the coast roads from La Grande Charriere through the Dicq and Havre des Pas and from Gloucester Street right along to St Aubin were flooded and closed to traffic.

February 11: This morning’s high title combined with gale-force winds from the south to cause some of the worst damage on exposed south coast areas in many years. Hardest hit was Gorey where the harbour took the full force of the storm and a number of boats were wrecked. Tens of thousands of pounds worth of damage was caused at Gorey in what was described by a veteran fisherman as " the worst storm in living memory”. The occupants of two sea-lashed cottages at Gory say they were afraid to sleep in their homes tonight because of the possibility of more serious damage.

March 9.-The full extent of the damage to the early potato crop caused by the severe frost earlier this week has not yet been ascertained, but it is expected to be quite serious.

September 2.---Mountainous seas and gale-force winds lashed Jersey's east coast this morning leaving a trail of destruction from Gorey to St. Catherine for the second dine this year. At least three valuable boats were smashed against the rocks until they were nothing more than drift wood, and several other craft suffered minor damage after dragging their moorings and pounding against harbour walls.

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